1. Field of the Invention
The present invention relates to an electrostatic discharge (ESD) protection device, and more specifically, to an ESD protection device for a pushbutton module.
2. Description of the Related Art
Electrostatic discharge (ESD) occurs in device measurement, packaging, installation, and usage, often damaging integrated circuits (IC) and affecting functionality. Three common models illustrating the formation of ESD are human body model, machine model, and charge device model. The human body model describes the ESD effect induced when the pin of an IC is contacted by a human being carrying electrostatic energy, defined according to Method 3015.6 of Military Standard (MIL-STD.-883). The machine model describes ESD induced when the pin of an IC is contacted by a machine carrying electrostatic energy, defined according to the measurement method in Method 20 of the Electronic Industry Association of Japan (EIAJ-IC-121) standard. The charge device model describes an ESD pulse generated in a charge carrying IC when contacting a grounded conductive element.
Most electronic devices experience ESD during 99% of their life cycle, and ESD interference in an electronic device can cause device lock up, restart, data loss, and reduced in reliability. ESD can seriously damage I/O ports, resulting in hardware breakdown and component damage.
Component failure is an obvious symptom of ESD damage, wherein contact with sensitive components destroys the components or microcircuits thereof. Although the electronic components subject to electrostatic discharge often suffer insignificant damage, the degradation of the middle layer is a potential issue as the expected lifetime of the component is less than claimed. ESD damage can accumulate, such that the performance of the influenced component varies from use to use. Another key effect of ESD is the influence on operation. The ESD generated energy can be mistakenly collected by the operating device as valid data, resulting in temporary failure during data transmission, or more seriously, physical damage to the device, such as damage to electronic components in a pushbutton module.
Push button switches are currently widely used, but the discussed ESD problems are is still an issue. In order to prevent electrostatic accumulation, an appropriate approach is required for avoidance of ESD generation.